X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Farch%2Fx86%2Fmm_virt.c;h=c930947dedfbf2444dea6d25cedd93c32bde3e3f;hb=abecaa9215f064b5b5631852fd809b63f1379c93;hp=25da74336ca5f2182ff8ab1145900e42279be49f;hpb=0c641aba30830a011f7e82aca119c541884d8aab;p=tpg%2Facess2.git diff --git a/Kernel/arch/x86/mm_virt.c b/Kernel/arch/x86/mm_virt.c index 25da7433..c930947d 100644 --- a/Kernel/arch/x86/mm_virt.c +++ b/Kernel/arch/x86/mm_virt.c @@ -9,6 +9,7 @@ * 0xFE - Unused * 0xFF - System Calls / Kernel's User Code */ +#define DEBUG 1 #include #include #include @@ -39,6 +40,8 @@ // === IMPORTS === extern Uint32 gaInitPageDir[1024]; extern Uint32 gaInitPageTable[1024]; +extern void Threads_SegFault(Uint Addr); +extern void Error_Backtrace(Uint eip, Uint ebp); // === PROTOTYPES === void MM_PreinitVirtual(); @@ -105,15 +108,32 @@ void MM_PageFault(Uint Addr, Uint ErrorCode, tRegs *Regs) && gaPageTable[Addr>>12] & PF_COW ) { tPAddr paddr; - paddr = MM_DuplicatePage( Addr ); - MM_DerefPhys( gaPageTable[Addr>>12] & ~0xFFF ); - gaPageTable[Addr>>12] &= PF_USER; - gaPageTable[Addr>>12] |= paddr|PF_PRESENT|PF_WRITE; + if(MM_GetRefCount( gaPageTable[Addr>>12] & ~0xFFF ) == 1) + { + gaPageTable[Addr>>12] &= ~PF_COW; + gaPageTable[Addr>>12] |= PF_PRESENT|PF_WRITE; + } + else + { + paddr = MM_DuplicatePage( Addr ); + MM_DerefPhys( gaPageTable[Addr>>12] & ~0xFFF ); + gaPageTable[Addr>>12] &= PF_USER; + gaPageTable[Addr>>12] |= paddr|PF_PRESENT|PF_WRITE; + } + INVLPG( Addr & ~0xFFF ); //LEAVE('-') return; } + // If it was a user, tell the thread handler + if(ErrorCode & 4) { + Warning("User Pagefault: Instruction at %p accessed %p", Regs->eip, Addr); + __asm__ __volatile__ ("sti"); // Restart IRQs + Threads_SegFault(Addr); + return ; + } + // -- Check Error Code -- if(ErrorCode & 8) Warning("Reserved Bits Trashed!"); @@ -127,6 +147,10 @@ void MM_PageFault(Uint Addr, Uint ErrorCode, tRegs *Regs) ); } + Log("Code at %p accessed %p", Regs->eip, Addr); + // Print Stack Backtrace + Error_Backtrace(Regs->eip, Regs->ebp); + Log("gaPageDir[0x%x] = 0x%x", Addr>>22, gaPageDir[Addr>>22]); if( gaPageDir[Addr>>22] & PF_PRESENT ) Log("gaPageTable[0x%x] = 0x%x", Addr>>12, gaPageTable[Addr>>12]); @@ -149,6 +173,24 @@ void MM_DumpTables(tVAddr Start, tVAddr End) const tPAddr MASK = ~0xF98; Start >>= 12; End >>= 12; + + #if 0 + Log("Directory Entries:"); + for(page = Start >> 10; + page < (End >> 10)+1; + page ++) + { + if(gaPageDir[page]) + { + Log(" 0x%08x-0x%08x :: 0x%08x", + page<<22, ((page+1)<<22)-1, + gaPageDir[page]&~0xFFF + ); + } + } + #endif + + Log("Table Entries:"); for(page = Start, curPos = Start<<12; page < End; curPos += 0x1000, page++) @@ -158,7 +200,7 @@ void MM_DumpTables(tVAddr Start, tVAddr End) || (gaPageTable[page] & MASK) != expected) { if(expected) { - Log("0x%08x-0x%08x => 0x%08x-0x%08x (%s%s%s%s)", + Log(" 0x%08x-0x%08x => 0x%08x-0x%08x (%s%s%s%s)", rangeStart, curPos - 1, gaPageTable[rangeStart>>12] & ~0xFFF, (expected & ~0xFFF) - 1, @@ -197,11 +239,18 @@ void MM_DumpTables(tVAddr Start, tVAddr End) */ tPAddr MM_Allocate(Uint VAddr) { + tPAddr paddr; // Check if the directory is mapped if( gaPageDir[ VAddr >> 22 ] == 0 ) { // Allocate directory - gaPageDir[ VAddr >> 22 ] = MM_AllocPhys() | 3; + paddr = MM_AllocPhys(); + if( paddr == 0 ) { + Warning("MM_Allocate - Out of Memory (Called by %p)", __builtin_return_address(0)); + return 0; + } + // Map + gaPageDir[ VAddr >> 22 ] = paddr | 3; // Mark as user if(VAddr < MM_USER_MAX) gaPageDir[ VAddr >> 22 ] |= PF_USER; @@ -215,13 +264,20 @@ tPAddr MM_Allocate(Uint VAddr) } // Allocate - gaPageTable[ VAddr >> 12 ] = MM_AllocPhys() | 3; + paddr = MM_AllocPhys(); + if( paddr == 0 ) { + Warning("MM_Allocate - Out of Memory when allocating at %p (Called by %p)", + VAddr, __builtin_return_address(0)); + return 0; + } + // Map + gaPageTable[ VAddr >> 12 ] = paddr | 3; // Mark as user if(VAddr < MM_USER_MAX) gaPageTable[ VAddr >> 12 ] |= PF_USER; // Invalidate Cache for address INVLPG( VAddr & ~0xFFF ); - return gaPageTable[ VAddr >> 12 ] & ~0xFFF; + return paddr; } /** @@ -346,10 +402,12 @@ Uint MM_ClearUser() } MM_DerefPhys( gaPageDir[i] & ~0xFFF ); + gaPageDir[i] = 0; + INVLPG( &gaPageTable[i*1024] ); } + INVLPG( gaPageDir ); - - return *gTmpCR3; + return *gaPageCR3; } /** @@ -359,7 +417,8 @@ Uint MM_ClearUser() Uint MM_Clone() { Uint i, j; - Uint kStackBase = gCurrentThread->KernelStack - KERNEL_STACK_SIZE; + Uint page = 0; + Uint kStackBase = Proc_GetCurThread()->KernelStack - KERNEL_STACK_SIZE; void *tmp; //ENTER(""); @@ -376,29 +435,31 @@ Uint MM_Clone() // Check if table is allocated if( !(gaPageDir[i] & PF_PRESENT) ) { gaTmpDir[i] = 0; + page += 1024; continue; } // Allocate new table gaTmpDir[i] = MM_AllocPhys() | (gaPageDir[i] & 7); - INVLPG( &gaTmpTable[i*1024] ); + INVLPG( &gaTmpTable[page] ); // Fill - for( j = 0; j < 1024; j ++ ) + for( j = 0; j < 1024; j ++, page++ ) { - if( !(gaPageTable[i*1024+j] & PF_PRESENT) ) { - gaTmpTable[i*1024+j] = 0; + if( !(gaPageTable[page] & PF_PRESENT) ) { + gaTmpTable[page] = 0; continue; } // Refrence old page - MM_RefPhys( gaPageTable[i*1024+j] & ~0xFFF ); + MM_RefPhys( gaPageTable[page] & ~0xFFF ); // Add to new table - if(gaPageTable[i*1024+j] & PF_WRITE) { - gaTmpTable[i*1024+j] = (gaPageTable[i*1024+j] & ~PF_WRITE) | PF_COW; - gaPageTable[i*1024+j] = (gaPageTable[i*1024+j] & ~PF_WRITE) | PF_COW; + if(gaPageTable[page] & PF_WRITE) { + gaTmpTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW; + gaPageTable[page] = (gaPageTable[page] & ~PF_WRITE) | PF_COW; + INVLPG( page << 12 ); } else - gaTmpTable[i*1024+j] = gaPageTable[i*1024+j]; + gaTmpTable[page] = gaPageTable[page]; } } @@ -599,7 +660,7 @@ Uint MM_MapTemp(tPAddr PAddr) return TEMP_MAP_ADDR + (i << 12); } RELEASE( &gilTempMappings ); - Proc_Yield(); + Threads_Yield(); } }